網球正拍擊球對軀幹肌電之影響

Abstract

目的：探討網球不同站位與方向正拍擊球在三個階段對軀幹肌電圖的活化表現。方法：以12位男性甲組網球選手 (右手持拍者) 進行2站位 (開放式站位、直角式站位) 與 2方向 (直線、對角線) 的正拍擊球，收集其腹外斜肌、闊背肌、豎棘肌左右兩邊的肌電圖，比較在三個階段 (準備期、加速期、跟隨期) 的差異。以CASIO數位相機的影像分階段。採用重複量數三因子變異數分析 (α = .05)，LSD法事後比較。結果：左腹外斜肌受到方向的影響，對角線比直線活化程度高。六個肌群都受到階段的影響，在加速期活化程度最高，右腹外斜肌、右闊背肌、右豎棘肌與左腹外斜肌在跟隨期次之、準備期最低，左豎棘肌在準備期次之、跟隨期最低。結論：正拍技術打擊對角線時，左腹外斜肌的訓練特別重要。正拍擊球時，左豎棘肌先行活化，決定軀幹開始向前揮拍動作的關鍵。Purpose: To investigate the change of electromyography (EMG) on trunk muscles during a tennis forehand stroke in different stances and directions. Methods: Twelve advanced males tennis players (right handed) performed two stances (open& square stance) and directions (crosscourt & down the line) forehand stroke. The left and right external oblique (LEO & REO), latissimus dorsi (LLD & RLD), and erector spinae (LES & RES) EMGs were collected and compared. The image time of every motion recorded by CASIO digital camera was divided into the preparation, acceleration and follow through phases. A 3-way ANOVAs of repeated measures (α = .05) and LSD for posteriori comparison were used for analysis. Results: The LEO muscle activation was affected by directions. The EMG of crosscourt hits was greater than down the line hits. The interaction of directions and phases impacted on REO, while LES was influenced by the interaction of stances and phases, but they both were no significant in three phases. Also, six muscles were affected by phases. The activation in the acceleration phase were the hightest, except for the LES, the transforming percentage of peak was greater in the preparation phase to the follow through phase, others five muscles changed from the follow through to the preparation phase. Conclusion: It’s important to train LEO muscle to intensify forehand drive crosscourt. During a tennis forehand stroke, LES muscle will activate first. It is the key point to start the force for the trunk with forward racket swing.